Well, my fourm is here:
http://ghostdogs.net/bb/
Not sure why you need admin login in..... Anycase, yes the template for my phpBB [SubBlack] uses a css file. I do not know a lot about this file but I have "tweaked" it before.
You can take a look at my site, it is very heavly MOD'ed with phpBB Mod's. It is not very standard at all. While I do not know how to Code, I do know how to read install.txt files and look for help when I run into problems.